This invention relates to a shutter which can be folded and housed on rails.
Sliding and wind-up methods have been available for housing folding and wind-up type shutters which are needed because of the small spaces that they require for housing.
Through the development of shutters provided with wide slats, a mechanism to fold each slat for housing was developed to take the place of noisy wind-up type housing mechanisms.
To design a housing mechanism of zigzag folding as mentioned above, the hinges connecting the slats must be folded in opposite directions.
Taking slat thickness into consideration, a set of link type hinges have been used for connection at both sides of the butt surface of the slats 1, so that the slats can be turned as is shown in FIG. 1.
Because of these hinges 4, the slats can be turned in forward direction as shown in FIG. 1 or in an opposite direction as shown in FIG. 2 when the shutter is housed. (Broken lines in these drawings show the rails.)
With this hinge mechanism, however, a large clearance 11 is created between the adjacent slats 1 when the slats turn as shown in FIGS. 1 and 2.
The gaps are also made by the weight of each slat itself when the shutter is lowered, causing difficulties such as allowing rain to come inside through the gaps, large noises as slats collide with each other, and the risk of fingers being caught between the slats. Another trouble is that the slats do not turn smoothly.